Water-in-oil emulsions separation using an ultrasonic standing wave coalescence chamber

Carlos Mario Giraldo Atehortúa; Nicolás Pérez; Marco Aurelio Brizzotti Andrade; Luiz Octávio Vieira Pereira; Julio Cezar Adamowski

doi:10.1016/j.ultsonch.2019.04.043

Water-in-oil emulsions separation using an ultrasonic standing wave coalescence chamber

Ultrason Sonochem. 2019 Oct:57:57-61. doi: 10.1016/j.ultsonch.2019.04.043. Epub 2019 Apr 29.

Authors

Carlos Mario Giraldo Atehortúa¹, Nicolás Pérez², Marco Aurelio Brizzotti Andrade³, Luiz Octávio Vieira Pereira⁴, Julio Cezar Adamowski⁵

Affiliations

¹ University of São Paulo, Department of Mechatronic and Mechanical Systems Engineering, Sao Paulo 05508-900, Brazil.
² Universidad de la República, Facultad de Ingeniería, Montevideo 11300, Uruguay.
³ University of São Paulo, Institute of Physics, Rua do Matão, 1371, São Paulo 05508-090, Brazil.
⁴ PETROBRAS/CENPES, Av. Horácio Macedo 950, Ilha do Fundão, Rio de Janeiro 21941-915, Brazil.
⁵ University of São Paulo, Department of Mechatronic and Mechanical Systems Engineering, Sao Paulo 05508-900, Brazil. Electronic address: jcadamow@usp.br.

PMID: 31208619
DOI: 10.1016/j.ultsonch.2019.04.043

Abstract

The offshore extraction of crude oil produces stable water in oil emulsion. To separate this emulsion into oil and water phases, the oil/water interfacial film is commonly destroyed by the addition of chemical demulsifiers. The use of an ultrasonic standing wave force field could be an alternative to reduce the dosage of chemical demulsifiers in the coalescence process. In this work, an ultrasonic separator of water in crude oil emulsions is investigated through the use of a high frequency ultrasonic standing wave coalescence chamber. The coalescing chamber uses the acoustic radiation force to induce the coalescence of water droplets at the pressure nodes of a standing wave field. Due to temperature fluctuations, the excitation frequency is controlled to maintain the resonance in the coalescence chamber and the voltage amplitude is controlled to deliver a given acoustic power. Experimental tests using standardized emulsions of water in oil were carried out in a laboratory processing plant. The effects of ultrasound application, flow rate, initial water content, demulsifier dosage and chamber inlet temperature were analyzed. The results show that the use of the acoustic radiation force improves the emulsion separation in all the conditions analyzed, when compared with the gravitational separation technique.

Keywords: Frequency tracking; Ultrasonic coalescer; Water-in-oil emulsion.